The current air traffic control system depends on radio voice communications between pilots and air traffic controllers for safe flight operations. FIG. 1 shows a schematic diagram 100 of a conventional system for managing airspace flight control information. In FIG. 1, only one flight path 110 and three aircraft 102-104 are shown in sector-A for the purpose of brevity, even though there are, in general, multiple flight paths in each sector and multiple aircraft in each flight path. Typically, the pilots of the aircraft 102-104 communicate radio signals 122 with controllers in a control tower 120 to exchange various types of information, such as aircraft movements, aircraft vertical and lateral separation, operation clearances and aviation weather services.
Radio voice communications may present several problems. First, the voice communication between air traffic controllers and pilots operates essentially as a conference call, with the controller and the pilots of the aircraft 102-104 share the same radio channel. This has several consequences. First, pilots flying over the same sector may accidently step on the communication of other pilots or air traffic controllers. As repeated attempts to communicate are made, time is wasted. Second, to establish communication, a radio channel is reserved for a pilot's, say the crew of the aircraft 102, and the air traffic controller's use even when neither is sending the other a message. Thus, there is a saturation point where an air traffic controller cannot handle any additional voice radio communications.
To address these problems, a Controller-Pilot Data Link Communications (CPDLC) system has been introduced. The CPDLC system is designed to replace voice based clearances and readbacks between the pilot and air traffic controller by exchanging messages in an unambiguous digital format between aircraft and controller's computer. When either party's computer receives a message, the computer will display the text of the message for the pilot or air traffic controller to read and acknowledge. Thus, the pilots and controllers can exchange precise information without the problems associated with using radio voice communications.
The CPDLC system uses message sets that include clearance and response message and a numerical code associated with each message that is transmitted between the pilot and controller computer. For instance, the pilot of the aircraft 104 may set a message in the CPDLC system to request the altitude change during the flight path segment 108, to thereby avoid the turbulence 106, to the air traffic controller. In response to the message, the air traffic controller may send an authorization message in the similar digital data format to the flight management computer of the aircraft 104, which in turn converts the message into text message and displays it on a monitor to the pilot.
The existing CPDLC system has three problems. First, the pilots can be inundated with information that the flight management computer provides. This can cause the pilot to waste time isolating and focusing on the information that he/she needs for the task at hand. When the flight requires the pilot to perform many tasks within a short period of time, such as approaching a runway and landing, the time wasted by the pilot can force the pilot to inadvertently miss valuable information or ignore valuable information to keep abreast of the required tasks.
Second, the pilot cannot receive message aurally from the aircraft's CPDLC computer or control the aircraft's CPDLC computer using spoken command because the flight management computer of an aircraft is typically not connected to the cockpit audio system. Spoken commands allow the pilot to use his hands for other tasks in the flight while communicating with the ground controller.
Third, the aircraft pilot would prefer to receive information, such as weather patterns, obstructions and other conditions that may interfere with a flight plan, formal or informal, as the pilot flight proceeds, with a latency of no more than a few minutes. Referring back to FIG. 1, the pilot of aircraft 104 may send a pilot report (PIREP) when the pilot encounters a substantial weather event, such as turbulence 106. The PIREP is received by the air traffic controller at the control tower 120, and may be stored in a database. A pilot of the aircraft 102 may request the PIREP before his own flight begins. If the pilot of the aircraft 102 receives the PIREP containing the information of turbulence 106 before his departure, he would be able to utilize the information to thereby avoid the turbulence 106. However, if the PIREP was received after the pilot started the flight, he would not be aware of the turbulence 106 to take any proper action in advance. In general, a PIREP can be associated with a latency of one to six hours. Thus, learning of, and reacting to, a changing environment within minutes after the change is first observed and reported is not possible with existing PIREP system.
Therefore, there is a need for a system that can provide aural information to pilots in cockpits of aircraft on real time basis, to thereby remove most of the latency associated with PIREP and allows expansion of, and selective filtering of, information that is directly useful to the recipient pilot.